But monsters often attack you from different directions, so dodging projectiles from only 1 direction may not be enough. Individual monsters are at different distance from you, so projectiles arrive at your location at different moments. On many occasions a projectile you dodged once becomes dangerous again, because you have to dodge another missile, go back etc. This is typically due to lack of space - you're on some platforms (above lava) and monsters are shooting you, or in tight corridors.
DooM is largely a projectile-dodging game. Among FPS games, DooM has exceptionally high number of projectiles to dodge. Although Heretic actually has more...

Yes, it's another way of looking at DooM. While individual enemies except Mancubus don't shoot around player, there are often so many monsters ! So many imps, mancubi. And advanced players learn to dodge Revenant missiles in the open rather than rely on the cowardly corner trick all the time.
So saying that DooM is simply outdated is missing the point. It a completely different style of a game. Just like Realm Of The Mad God is the only action RPG which qualifies as bullet hell. It's a MMORPG with autofire !! That makes it look more oldschool than DooM.
http://realmofthemadgod.com
If John Carmack and company weren't so close-minded, I would totally pay for a "bullet hell FPS" kickstarter project. Bullet hell FPS genre is completely extinct, you could even say no one really tried it to its full potential. Hexen had parts of bullet hell - in many places traps would shoot projectiles from walls, but 1) they were often not dodgeable, like too short distance 2) Hexen was never really about combat mechanics. Out of DooM engine games it has worst combat and very questionable level design (but perhaps the best atmosphere).
A very cheap yet effective way to make Bullet Hell DooM: give player permanent partial invisibility ! How evil !

It occured to me that there's one more way in which DooM (and Heretic) is unique.
It's the best example of a bullet hell FPS. Reasons:
- the majority of monsters shoot projectiles
- those projectiles are dodgeable
- player speed is high compared to missile speed
- monsters often come in swarms
So we have:
Imp, Cacodemon, Hell Knight, Baron, Lost Soul, Pain Elemental, Revenant, Arachnotron, Mancubus, Cyberdemon. Even pinkies can be included because movement is critical to avoiding them.
It's NOT a stretch to say dodging is more important than aiming, in DooM. This is a typical trait of a bullet hell game.
It could be a fun idea for a mod: make DooM even more of a bullet hell ! Zombiemen, shotgun guys, heavy weapon dudes would shoot verrry fast (but dodgeable) missiles. Even Spider Mastermind could do that. With its spread and rate of fire it wouldn't be trivial.
I want more games like that. I don't think Serious Sam qualifies. Too many melee monsters.

In E4M6:
http://www.youtube.com/watch?v=KzUVNlVExNI
Look where the crossbow is. Near the yellow door, in the room with Iron Lich and there are multiple saberclaws barring the way :-)
No, you don't have enough crystals to kill gargoyles before entering the room.
No, you don't have enough crystals to kill all the saberclaws, let alone the iron lich.

It does, at first. Then you realize there are no graves, no coffins, etc. Just a maze of tricky corridors.
Heretic levels in general seem closer to their names than DooM levels, and still play very well. River of Fire looks like a river of fire. So does Glacier, Cemetery, Docks...
They also have a few quirks:
- you find yellow key, then green key, then blue key. Always in this order. This makes navigation easier, you know where to go.
- there are very few traps where monsters teleport in. There are also no fast doors, so monster closets are a bit more forgiving.

I've just completed E5M4. Not particularly difficult. The swarm of nitrogolems at the start is inconvenient, of course, but you only need to push your way past them. The path is linear and soon you arrive at the comfy room with gargoyles and the crossbow. Then I backtrack to collect backpack and ammo, and kill undead warriors via secret. For killing nitrogolems the door is very useful. Aim a little down, open door and close after each shot.
E4M9 is another matter. It's not even that there are swarms and almost no weapons. The map itself is confusing as hell, no landmarks, everything looks the same basically. Secret doors required to progress. I had to use "killall" cheat on lower difficulty and still had problems finding the first door. Then I checked a speedrun on youtube.
The main difficulty seems to be orienting in the mausoleum while under fire. You have to memorize where the teleporter chamber is or you're dead within seconds.

Hi
1. Select "Black Plague Possesses Thee" skill level - the highest.
2. Use a cheat to warp to E1M9. You should only get starting equipment.
3. No prisoners, no survivors.
Quite hard actually. I won't spoil things for you, there are unexpected complications. And 'invisible' undead warriors are perhaps the most brutal monsters in the game.
Does anyone else know levels which are similarly hard when played from scratch ? It could also be from DooM, DooM II, Hexen. Hexen is the least suited for this(some hubs are impossible to finish if you start in the wrong level), and it's a bit easy to predict the hardest combination. Almost invariably Cleric because he starts with a pathetic weapon.

I'm afraid he may have given up playing DooM II. It's been several days since last video, and they appeared daily prior to that.
It's quite interesting to see a newbie's perspective. The part I enjoyed the most is when he started getting his ass handed to him.

I remember at one point SS said with irritation they don't want any more snail mail telling them how to beat the boss in DooM II. Pure gold.
As for how the myth came to be, my bet is on ignorance. They may have even written the review before finishing DooM normally, they were only able to reach the level with cheats. Unable to find the way, after an hour of killing monsters aimlessly, they chalked it down to cheat protection. It's not completely insane - remember, DooM doesn't allow cheats on Nightmare skill.

Baron of Hell vs Hell Knight - it sounds cheap at first, but remember that even back then Barons were considered mostly harmless bullet sponges. I remember reading an interview or something mentioning that they introduced Knights as the less boring version. They deal just as much damage but don't require as much time to take down. If you're still not convinced, Heretic has so many monster variations and most of them don't even look different !
Come on, even DooM diehards and fans should admit not everything in DooM was perfect:
* The bosses except glorious and frighteningly powerful Cyberdemon were uninspired at best. Spider Mastermind in particular is a letdown as a final boss.
* Super Shotgun not so much adds to the game as replaces the ordinary one. You have to bend over backwards to find a reason to use Shotgun, when SSG deals 3x damage for only 2x ammo.
* melee monsters are infamous for being pathetic. I can't think of a game where melee monsters were more of a joke. Demons simply can't deal damage to an alert and sober player in vast majority of cases. Almost all exceptions are workarounds like placing demons in groups or placing them in confined spaces. Lost Souls aren't much better.
* melee weapons are very hard to use mostly because they're buggy. Fist is hard to hit with even if you touch the monster. Arachnotrons, Mancubi would make great chainsaw targets if it wasn't for the cross-section and blockmap bugs.
* Infinitely tall monsters. There's an imp somewhere below, and None Shall Pass. It often turns into a guessing game when you try to find a way down.
* Partial Invisibility is just harmful unless there are only hitscan monsters around. It could've been changed to be useful for everyone with some creativity. Make it so monsters shoot at the spot you were 0.5 second ago. That's a lot of time in DooM.
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As for things that DooM genuinely lacked, in my opinion:
Grenade launcher. Not to bounce behind corners, but to hit stuff in various pits.
Interesting flying monsters. There are only cacodemons, which are limited by their huge size, and skulls. Gargoyles in Heretic are an excellent counterexample. They work just about anywhere and are fun to fight. 2 more flyers with unique mechanics would be great.
At least a token way to have path over path. Flying magical bridges like in Hexen would be okay, they would even fit in the Hell episodes and some monsters appear to use magic anyway.
I disagree about landmines. Would slow the game down, and would enable grind (place mine, lure monster, place mine, lure monster, place mine... not very fun).